Stunning in a custom Jorge Vega Umana dress, the actress wed longtime love Neil Mody, the CEO of nRelate, on an island in Mexico.
The newlyweds exchanged vows Saturday in the sand at sunset, the highlight of a three-day affair many, many days in the making.
"Neil and I met when we were 18 years old and studying at NYU together," Sheth, 37, whose movie credits include I Can't Think Straight (2008), The World Unseen (2007) and Three Veils (2011), tells PEOPLE. "He is my first and truest love. Despite experiencing many years of ups and downs, the stars aligned, and we found our way back to each other."
The couple rented out an entire resort for their guests, including Aasif Mandvi, Amir Arison, Craig Armstrong and Nazanin Boniadi.
"Being able to have all of our favorite people in one place to celebrate over a weekend is a true blessing," adds Sheth, whose upcoming sci-fi film, The Wisdom Tree, arrives in theaters in January. "Not only am I lucky enough to marry the best person I know, I get to share in all the love with the best friends and family anyone could wish for."
The newlyweds will also celebrate their marriage alongside 450 revelers at a New Jersey reception next week.